Harmattan dust mass over Ilorin a Guinea Savanna African City

Abstract

Harmattan season in Nigeria is the period during which dust cover the atmosphere as a result of aerosol particles being transported from the Sahara region of Africa. Samples of these dust particles were collected over Ilorin (8° 32' N, 4° 34' E) guinea Sahara region of West Africa using clean Petri-dishes which were exposed on the ground level and an elevated platform of five meters above the ground level in twelve different locations within Ilorin metropolis including the University of Ilorin. Some of the dishes were exposed to collect dust particles for a period of eight weeks between January and March while some other sets were left over a period of three months (January-March). The samples were stored in desiccators prior to analysis in order to avoid contamination which could influence the results. It was observed that more and heavier dust samples were collected on the ground levels which are of average size of (9.70g/m2)compared to those collected at an elevation which are of average size of (7.10g/m2). At a particular location, Olunlade (8044'764''N, 4058'398''E) area of Ilorin, the volume of dust collected was higher than that of all other locations. In conclusion, the weight of harmattan in Ilorin is found to be lower in mass as compared with locations further north of Nigeria.